Consider data from a series of photoelectric experiments on a
single sample, where the photocurrent 
is measured as a
function of applied voltage V and the brightness B and frequency
of the light source.
Why, for fixed values of V and 
, are we guaranteed that
always gives the same value regardless of B?
Will 
give the same value regardless of 
? That
is, must we get the same current if we increase the energy of the
photons but simultaneously decrease by the corresponding amount the
potential we use to gather the
electrons? Why or why not?\
Hint: You may wish to sketch a few example graphs to get a feel
for what is going on.